Of course, the book will always be "better" than the movie, but I thought the movie was excellent.
It was tightly put together, using imagery shorthand to convey the message and make transitions instead of lengthy exposition. Where the book provides multiple examples to establish character developments, the movie might include one or two. For this reason, a lot of the details of the book are left out, and the viewer is left with impressions that the book fleshes out fully. But I see this as a strength of the movie (a visual medium), rather than a weakness. I think the director and writers chose their book moments wisely. I enjoyed the performances, the pacing moved briskly, and I left wanting to watch it again immediately.